Electric bell.



H. R..STUART @E RSBAEFER. ELECTRIC BELL. .A.1Pr.1 m'1.1o1 FILED rma. zo, 1912.

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HARVE REED STUART, F SPRINGFIELD, OHIO, AND FDERIG-SCHAEFER, '0F

i PITTSBURGH, PENNSYLVANIA.

ELECTRIC BELL.'

Specification of Letters Patent.

Application led February 20, 1912. Serial No. 678,796.

To all whom it may concern:

Be it known thatwe, HARVE REED STUART, a resident of Springfield, in the county of Clark and State of Ohio, and FREDERIC SCHAEEER, a resident of Pittsburgh, in thev county of Allegheny, State of Pennsylvania, have invented a new and useful Improvement in Electric Bells, of which the following is a specification.

This invention relates to electrically actuated signaling devices, such as bells. v

The main object of the invention is to provide an electrically actuated signaling device which can be connected to ordinary' commercial alternating circuits without the intervention of a transformer and whereby dangerous grounds or short circuits are guarded against.

Further objects are to provide mechanism of strong, reliable, and yet cheap construc- 1on.

The invention comprises the circuit connections and arrangement of parts hereinafter described and claimed.

In the accompanying drawings Figure 1 shows partly in plan view and partly dia- Y grammatically an electric bell embodying the invention; Fig. 2 is a diagram showing a modification; and Fig. 3 isa detail view of the armature and ball tappcr.

The signaling device has'been illustrated as an ordinary bell or gong 1 of usual constructionxadapted to be sounded byl a vibrating hammer or clapper 2, carriedl by an oscillatory armature 3 lvotally mounted at 4 intermediate its ends. Adjacent to the opposite ends of the armature are a pair. of

poles 5 and 6 one opposite each end ofthe armature. These are formed as extenslons from one arm or pole of a strong permanent magnet 7 of horseshoe form, the armature being pivotall mounted adjacent to the opposite pole o said armature. The conseuence 1s that the two poles 5 and 6 are of t e same polarity when no current is circulating through the windings, while the ar-l mature 3 is of the opposite polarity.

ranged to be connected "Ste sides of the line. As shown, one sidey Surrounding each of the extensions and 6' is a' magnet coil, the two coils being marked 8 and' 9, respectively, and are arrespectively in oppoof the line 10 is Lconnected to bindinggpost Patented Dee. 31,1912.

11. To the same post is connected one end 12 of coil 8, the opposite end 13 of said coil being connected to binding post 14:. The other side 15 of the line is connected to binding post 16. To the same. binding post is connected one end 17 of coil 9, the other end 18 of said coil being connected to binding post 19. To the binding posts 14.- and 19 are connected circuit wires 20 and 21, respectively, in which are connected one or more circuit closers or push buttons 22 for the purpose of closing the circuit to actuate the bell.

It will be observed that the two coils 8 and 9 are connected respectively in opposite sides of the circuit, and that the circuit closer or push button is in series with both coils and between the same. The coils 8 and 9 are composed of turns of very line wire, having high ohmic resistance, and very material self-inductance, so that they choke or cut down the current, to allow only a very small amperage to How through the coils.

is again broken. Since the push button is between the coils, a safeguard is provided against dangerous grounds or short circuits between the button wires 20 and 21 and one side of the line which would exist if the circuit closer were in series with the two coils and between one thereof and one side of the line. When no current circulates in the coils both cores are ofthe same polarity, sa N poles, while the armature presents S7 poles, these poles being induced by the permanent magnet. Upon closing the circuit at 22 the alternating current Hows through the two coils 8 and 9 in series. Whenone-half of the wave is flowing, the N pole of one coil is strengthened or Vbuilt up, while the pole of the other coil is weakened and may even be reversed so as to become an S ole. The armature, however, remains of t e same polarity as before. Its one end is, therefore, `attracted strongly by the strong N pole, while its opposite end isiscarcelyvattracted at all by the weak i f Nv pole or 1t may even be repelled should vthis pole be of S polarity. When the following half of the wave flows through l 5 thecoils, the conditions` in the coils are reversed and the armature is attracted in the opposite direction. The consequence is that with an-alternating current the poles 5 and 6 are alternately strengthened and weak- 10 ened to produce oscillation of the armature 3.' l 4 llVhen one endof the armature is 'in contact with the .correspondin pole, say the pole 5, there isa considera le'air gap between the opposite end of the armature and theA pole 6, v which must be overcome before attractionbetween the contacting pole 5 and armatlll'ecan be broken.V The consequence is that Vthe 'pole 6. must be, materially strengthened before the pole 5 releases the the relatively great strengthA 'ofthe opposite pole bringsfthe armature in' contact therewith with a snap, which produces ener- Vgfgetic actuation of, the .armature and energetic operation 'of the bell. lf Athe "armature would vibrate upon'very small dierences in strength of the two poles 5 and- 6 only ieeble actuation of the bell could result, but by having the two poles 5 and 6 ofthe saine polarity and relatively strongy magnetism, it requires a much greater variation in the strength of the two poles to produce oscillation of the armature, but the oscillations 7,35 will be much more energetic, as just pointed .,out. The consequence is a strongsignal. A A

Fig. 2 shows a modification in which one of the coils is split, one part 8?' surrounding 40 one lcore 5 and the other part 8P surround-- ing the other core 6, along with the other coil 99t- 'lhe eiiect here is the. same in principle as in the preferred form.

By having relatively weak coils the device is rendered com aratively inexpensive', as

- the spools or enig constitute a considerable' item of expense, particularly where these coils must be large and strong. j

' The bell described can be connected directly in any commercial alternatingcircuit',

Vthe most common of which are of 110 volte.-4

that the device gives 4It operates perfectly uponV an alternating" circuit of this voltage, without the use ot a transformer 'and without dangerous grounds or short circuits. On account of the high resistance and self-inductance of thev coils A the current is out down andthe voltage Lalso dro s suddenly" at thecircit closer as soon as t elatteriis closed, and the location of the circuit closer between the-two sections of coil prevents dangerous grounds "and shortscirji cuits, as herelnbefore pointed out, and thismakes it safe to use the heli'l upon relatively hgh voltage circuit without the use oit a transformer;

Aespecially advantageous, as it entirely obv-i. ates evil effects in case of short clrcuits. larmature, and when the latter is overcomeV with, an armature arranged t0 be vactuated winding, and

meente The signal device can be of any' character 'adapted to be actuated by the oscillating armature. llt neednot necessarily be abell or gong. For the purpose of strength, the armature 3 and hammer or clapper 2,'.and' preferably also the pivots 4, are made of a single piece so as to withstandsevere vibration. This is shown in Fig. 3.

A short circuit between opposite sides of the circuits to the coils 8 and 9 has no other effect than to ring the bell'. For instance a short circuit between wire 12 or 'wire' 13 and wire 18 or binding post 19, or between wire 17 or wire 18 and wire 13 or binding post 1li produces the same effect as if the circuit closer-22 were closed. The circuit arrange-n ment shown with a coil on each 'side of the push button or circuit closer is therefore'f 85 What we claim is: 1. In an' alternatin current signal, the combination of a win 'ng in two parts, the y two parts arranged'to be connected, one inlY one sident Vthe line andthe other in the other side of the line, a current closer ar -:ranged to be connected between the two parts of the winding and in series thereby said winding, and a signal device actul ated-from said armature.

2. ln an alternating rcurrent signal, the combination of a winding in two parts, the' two parts arranged to be connected, fone in? one side ci the line and the other in the other side of the line, ermanently ma etized cores -for said windings, a circuito oser erranged` to be connected between the two parts ofthe winding and in series therewith an armature arranged to be actuatcd'by sai a signal device'actuated, fromsaid armature.

i .3., ln an alternatinei current signal,` the;

combination et a win ing vin two partsg-the two parts arranged to be connected, one 1n one side of the line and the other in the other side; oi the line,permanently'magnet# f ized cores of the same polarity :for said w1ndings, a circuit closer' arranged to bacon" nected between the two parts of the winds .ing and in series therewith, an oscillatory. 'armature arranged to be actuated by said winding and a signal deviceactuated from Li. 11i-ani alternating current electricsig-v nal,'the combination of a pair of coils, one ,connected in one side, ofthe line'and the other in the other side `oi lthe line,f\perma nently magnetizedpoles for said coils', an-` oscillating armature adjacent to?, saidf poles attraction of lsaid poles', acircuitcloseriin" series-with the coils gdgbtwehyhe; and a signal-'device actu' '1 bythe oscillation of caida-finiture." f-f 12'5 arranged to be' oscillated :Wemag-dma@ i 1 5. In an alternatin current electric signal, the combination o a permanent magnet, a pair of extensions from one pole thereof, a coil on each extension, one coil arranged to be connected to one side of the line and the other to the other side of the line, an oscillating armature arranged with an end adjacent toa pole of, each of said coils, a circuit closer arranged to be connected in series with said coils and between the same, and asignal device arranged to be actuated by the oscillation of said armature.

Witnesses to the signature of said Stuart:

FLORENCE I. JAYNEs, JOHN SUMMERS.

fer.

E. L. HYDE, MARY E. CAHooN.

Witnesses to the signature of said Schae- 

